Use a larger dtrace kernel buffer

tools/isolate/trace_inputs.py

 #!/usr/bin/env python
 # coding=utf-8
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Traces an executable and its child processes and extract the files accessed
 by them.
 
 The implementation uses OS-specific API. The native Kernel logger and the ETL
@@ skipping 1669 matching lines @@
       # but works fine enough.
       self._dummy_file_id, self._dummy_file_name = tempfile.mkstemp(
           prefix='trace_signal_file')
 
       # Note: do not use the -p flag. It's useless if the initial process quits
       # too fast, resulting in missing traces from the grand-children. The D
       # code manages the dtrace lifetime itself.
       trace_cmd = [
         'sudo',
         'dtrace',
-        '-x', 'dynvarsize=4m',
+        # Use a larger buffer if getting 'out of scratch space' errors.
+        # Ref: https://wikis.oracle.com/display/DTrace/Options+and+Tunables
+        '-b', '10m',
+        '-x', 'dynvarsize=10m',
+        #'-x', 'dtrace_global_maxsize=1m',
         '-x', 'evaltime=exec',
         '-o', '/dev/stderr',
         '-q',
         '-n', self._get_dtrace_code(),
       ]
       with open(self._logname + '.log', 'wb') as logfile:
         self._dtrace = subprocess.Popen(
             trace_cmd, stdout=logfile, stderr=subprocess.STDOUT)
       logging.debug('Started dtrace pid: %d' % self._dtrace.pid)
 
@@ skipping 1088 matching lines @@
       for fn in dir(sys.modules[__name__])
       if fn.startswith('CMD')))
 
   command = get_command_handler(argv[0] if argv else None)
   parser = gen_parser(command)
   return command(parser, argv[1:])
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))